Spindle-shaped component for an air-jet spinning arrangement with an injection channel

ABSTRACT

A spindle-shaped component for an air jet spinning arrangement is described. The component includes a base body and an attached tip, as well as a yarn withdrawal channel which extends through the base body and the tip, the first part of the yarn withdrawal channel being an entry opening in the tip. The spindle-shaped component also has an injection channel which runs into the yarn withdrawal channel, the injection channel being directed in the direction of the entry opening of the yarn withdrawal channel. The injection channel is formed by a surface area of the base body and a surface area of the tip.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to German Patent Application No. 102006018249.9, filed Apr. 13, 2006, the entire disclosure of which is herein expressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a spindle-shaped component for an air jet spinning arrangement having a base body and an attached tip, also having a yarn withdrawal channel which extends through the base body and the tip, the yarn withdrawal channel having an entry opening arranged in the tip, whereby the spindle-shaped component includes at least one injection channel which runs into the yarn withdrawal channel, the injection channel being directed in the direction of the entry opening of the yarn withdrawal channel.

The present invention relates further to a tip and a base body for a spindle-shaped component of this type.

A spindle-shaped component of this type is shown in German published patent application DE 10 2004 044 345 A1. During the spinning process, a fibre strand of staple fibres is fed to an air jet spinning arrangement and there the spinning twist is then given. In this process the fibre strand is initially fed through a fibre feed channel of the air jet spinning arrangement into a vortex chamber, to which a fluid device for generating a vortex current around an entry opening of a thread withdrawal channel is assigned. The front ends of the fibres held in the fibre strand are hereby fed into the thread withdrawal channel, while rear free fibre ends spread out, are seized by the vortex current and are twined around the front ends already located in the entry opening of the thread withdrawal channel, that is the ends that are already intertwined, whereby a thread, having to a great extent real twist is generated.

If the still very weak untwisted fibre strand or the spun yarn breaks, a piecing process must take place, in which the end of the already spun thread is fed back through the air jet spinning arrangement. For this process, an injection channel is arranged in the spindle-shaped component, which injection channel runs into the yarn withdrawal channel and is directed to the entry opening of the yarn withdrawal channel. This injection channel is subjected to pressurized air in a piecing process, so that in the air jet spinning arrangement, an air stream arises which flows in the opposite direction to the direction of spinning. By using the injection effect, a thread already spun can be sucked into the yarn withdrawal channel and transported through the air jet spinning arrangement against the normal spinning direction. The thread end guided through the air jet spinning arrangement can then be deflected in the known way and accordingly prepared, so that it can be joined to a newly fed fibre strand. After the fibre strand is pieced to this thread end, the spinning process is re-established.

The known spindle-shaped component has the disadvantage that the injection channel running into the yarn withdrawal channel is formed by a very thin borehole. The borehole for the injection channel is arranged in the tip attached to a base body of the spindle-shaped component. The borehole of the injection channel is drilled at an acute angle to the yarn withdrawal channel and has usually a diameter of several tenths of a millimetre. The manufacture of the injection channel is very complicated, as often the tip of the spindle-shaped component is made of a hard and wear-resistant material.

A different type of spindle-shaped component for an air jet spinning arrangement is known from German published patent application DE 103 49 651 A1, in which an injection channel extending in a different way is provided. The injection channel runs at right angles into a yarn withdrawal channel and is thus not directed in the direction of the entry opening of the yarn withdrawal channel. This placing of the injection channel has the disadvantage in that the injection action of the pressurized air stream into the yarn withdrawal channel is not as effective, so that a thread end necessary for the piecing process cannot always be reliably sucked against the spinning direction into the yarn withdrawal channel and transported through the airjet spinning arrangement. Due to the running of the injection channel at right angles into the yarn withdrawal channel, it can happen that the pressurized air flowing in also flows in a spinning direction through the yarn withdrawal channel, thus preventing a continuous air stream flowing against the spinning direction in the air jet spinning arrangement from occurring.

The present invention simplifies the manufacture of a spindle-shaped component of the above mentioned type.

According to exemplary embodiments of the invention, at least one injection channel is formed by a surface area of the base body and a surface area of the tip.

In this embodiment, the injection channel—seen in its cross section—is not surrounded by only one of the components base body or tip, but by both simultaneously. One section of the circumferential wall of the injection channel is formed by the base body and another section of the circumferential wall of the injection channel is formed by the tip. This has the advantage that the injection channel is not present in its entirety either in the base body or in the tip. The injection channel is formed then when the tip and the base body are joined together during assembly of the spindle-shaped component. The surface areas of the base body and the tip, which subsequently form in the injection channel when assembled, can thus be manufactured and machined separately. Manufacture is thus simplified as the very thin bore hole is no longer necessary.

It is advantageous when an injection channel is formed by a cone-shaped surface area of the base body and/or a cone-shaped surface area of the tip. With a cone-shaped surface area, it can be particularly well ensured that the injection channel, running into the yarn withdrawal channel, is directed in the direction of the entry opening of the yarn withdrawal channel, and also that the airstream directed against the spinning direction in the air jet spinning arrangement necessary for the piecing process, especially in the yarn withdrawal channel, is reliably generated when the injection channel is subjected to pressurized air. With a cone-shaped surface area at the base body or tip, the injection channel extends at an acute angle to the yarn withdrawal channel, namely at least in an area directly upstream of where the injection channel runs into the yarn withdrawal channel.

It can be provided that the injection channel at the finished spindle-shaped component is formed by a cone-shaped surface area of the tip, which is at a defined distance to a cone-shaped surface area of the base body. In an embodiment of the present invention it can be provided that a groove-shaped surface area either in the tip or in the base body is arranged to a cone-shaped surface area either in the tip or in the base body.

Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein:

FIG. 1 shows an enlarged view of an axial section of a spindle-shaped component and a respective air jet spinning arrangement during operation,

FIG. 2 shows an enlarged view of an axial section of another embodiment of the spindle-shaped component.

DETAILED DESCRIPTION OF THE DRAWINGS

The exemplary air jet spinning arrangement shown in FIG. 1 serves to produce a spun thread 2 from a staple fibre strand 3. A drafting device 4 is arranged upstream of the air jet spinning arrangement 1, which drafting device 4 generates a thin fibre strand 3 from a staple fibre band 5 and supplies it to the air jet spinning arrangement 1.

The staple fibre strand 5 is fed to the drafting unit 4 in drafting direction A and drafted to a desired degree of fineness in the known way. The partially shown drafting unit 4 is preferably a four-cylinder drafting device and includes therefore four roller pairs, each of which has a driven bottom roller and an upper roller designed as a pressure roller. Only the delivery roller pair 6, 7 is shown, which borders the drafting device 4. Directly downstream of the drafting unit 4 a thin fibre strand 3 is present, which is drafted and still twist-free.

The fibre strand 3 is fed via a fibre feed channel 8 to the air jet spinning arrangement 1. Downstream thereof lies a vortex chamber 9, in which the fibre strand 3 receives its spinning twist, so that the spun yarn 2 is formed, which is withdrawn through a thread withdrawal channel 10 in withdrawal direction B, and fed to a winding device (not shown).

The yarn withdrawal channel 10 in this example is arranged in a spindle-shaped component 11 stationary during operation, the component 11 including a base body 12 and a tip 13. The yarn withdrawal channel 10 includes an entry opening 14 for the forming yarn 2, which opening 14 is arranged in the tip 13.

A fluid device generates a vortex current during the spinning process in the vortex chamber 9 by blowing in compressed air through compressed air nozzles 15, which run tangentially into the vortex chamber 9. The compressed air exiting out of the compressed air nozzles 15 is discharged via an evacuation channel 16, whereby the channel 16 has a ring-shaped cross section around the spindle-shaped component 11, which comprises the thread withdrawal channel 10. The air evacuation channel 16 is connected with a vacuum source (not shown).

In the area of the exemplary vortex chamber 9, an edge of a fibre guiding surface 17, acting as a twist stop, is arranged, the fibre guiding surface 17 being slightly eccentrically arranged to the thread withdrawal channel 10 in the area of its entry opening 14.

In the air jet spinning arrangement 1, the fibres to be spun are, on the one hand, held together in a fibre strand 3, and thus fed from the fibre feed channel 8 into the thread withdrawal channel 10 essentially without a spinning twist, while on the other hand, the fibres in the area between the fibre feed channel 8 and the thread withdrawal channel 10 are exposed to the vortex current. The vortex current causes the fibres, or at least their end areas to be driven away radially from the entry opening 14 of the thread withdrawal channel 10. The yarns 2 produced by the above described air jet spinning arrangement 1 display a core including fibres or fibre areas extending essentially in a thread longitudinal direction without any significant twist, and an outer area in which the fibres or fibre areas are wrapped around the core. An air jet spinning arrangement 1 of this type permits very high spinning speeds, which lie in the range between 300 and 600 m per minute.

The compressed air exiting out of the compressed air nozzles 15 into the vortex chamber 9 is fed to the air jet spinning arrangement 1 during operation via a compressed air channel 18 and a ring channel 19 surrounding the vortex chamber 9. If the fibre strand 3 or the yarn 2 breaks, the compressed air feeding the compressed air nozzles 15 is shut off. At the same time, the drives of the drafting device 4 and of the yarn withdrawal rollers and the winding device (not shown) can also be shut down.

Before the necessary piecing process can be carried out, it can be advantageous to move the spindle-shaped component 11 away from the fibre feed channel 8 for a short time for cleaning purposes. During an exemplary operation a very small distance exists between the entry opening 14 of the yarn withdrawal channel 10 and the fibre guiding surface 17, which can measure, for example, 0.5 mm. The spindle-shaped component 11 can have a piston-shaped component 20, so that moving the spindle-shaped component 11 away can be carried out very simply. A ring channel 21 is arranged around the spindle-shaped component 11, which ring channel 21 can be subjected to compressed air. The compressed air in the ring channel 21 presses the piston-like component 20, attached fixedly to the base body 12 of the spindle-shaped component 11, upwards against the force of a spring 22 as shown in FIG. 1. The tip 13 of the spindle-shaped component 11 with the entry opening 14 of the yarn withdrawal channel 10 is moved aside by the fibre feed channel 8 and the fibre guiding surface 17, so that there is more space in the vortex chamber 9. Any fibre waste present on the vortex chamber 9 can thus be evacuated via the air evacuation channel 16. After the compressed air is shut off in the ring channel 21, the spring 22 presses the spindle-shaped component 11 back into its operational position.

In order to re-start the spinning process, a piecing process is now necessary, in which an end of an already spun yarn 2 is fed back through the yarn withdrawal channel 10 in the opposite direction to the withdrawal direction B, and then back through the entire air jet spinning arrangement 1 to the drafting device 4 in the opposite direction to the spinning direction. The end of the yarn fed back through the air jet spinning arrangement 1 can be joined with the fibre strand 3 in the exemplary drafting device 4 and the spinning process can be re-started. In the piecing process according to this example, an injection channel 23 is provided in the spindle-shaped component 11 for the purpose of feeding back the yarn 2, the injection channel 23 runs into the yarn withdrawal channel 10 and is directed to the entry opening 14. The injection channel 23 is subjected to compressed air during the piecing process and generates an air stream in the yarn withdrawal channel 10 and in the fibre feed channel 8, which flows in the opposite direction to the spinning direction to the drafting device 4. It is important that the injection channel 23 extends at an acute angle to the yarn withdrawal channel 10, before it runs into the same, so that the injection effect in the yarn withdrawal channel 10 is sufficient to ensure that the backward fed end of the yarn 2 is reliably sucked in. It can be advantageous to subject the injection channel 23 to compressed air already during the above described cleaning process in order to facilitate the cleaning of the vortex chamber 9.

In accordance with the exemplary embodiment of the present invention, it is provided that the injection channel 23 is formed by a surface area 24 of the base body 12 and a surface area 25 of the tip 13. The spindle-shaped component 11 is formed by the components base body 12 and tip 13. This is advantageous as the tip 13, in particular in the area of the entry opening 14 of the yarn withdrawal channel 10, is liable to a high degree of wear and is thus made from a wear-resistant material. A substantially cylindrical take-up part 26 is provided, via which the tip 13 is connected with the base body 12. The fixing of the tip 13 can hereby for example occur by using of a press fit or by using a screw thread on the take-up part 26. In order to provide a seal between the base body 12 and the tip 13, a sealing ring 27 can be provided, which, for example, can be made of copper.

The exemplary embodiment of the injection channel 23 according to the present invention gives rise to a particularly simple produceability of the spindle-shaped component 11, as the surface area 24 is machined during the making of the base body 12, while the surface area 25 is machined during the making of the tip 13. The surface areas 24 and 25 of the injection channel 23 are machined separately from one another before the spindle-shaped component 11 is assembled and give rise to the injection channel 23 only then when the tip 13 and the base body 12 are joined together. The injection channel 23 with its small cross section is not produced in its entirety, but rather is formed first when the surface areas 24 and 25 are arranged to one another when the spindle-shaped component 11 is assembled. When the cross section of the injection channel 24 is viewed, it can be seen that a part of its peripheral wall is formed by the surface area 24 of the base body 12 and another part of its peripheral wall is formed by the surface area 25 of the tip 13.

The surface area 24 of the base body 12 has a cone-shaped form, so that the injection channel 23 extends at an acute angle to the yarn withdrawal channel 10 and is directed towards the entry opening 14. The surface area 25 can be designed as a groove in the tip 13. The groove-shaped surface area 25 is arranged to the cone-shaped surface area 24, through which the injection channel 23 is formed. Alternatively, the surface area 25 may also have a cone-shaped form, and surround the cone-shaped surface area 24 at a short distance therefrom. This is denoted by the broken line with the reference number 25′. This would result, instead of a single injection channel 23, in a ring-shaped injection channel 23 extending around the yarn withdrawal channel 10.

In order to feed the compressed air to the injection channel 23, a groove 28 is provided in the area of the take-up part 26, which extends parallel to the yarn withdrawal channel 10, the groove 28 being connected with a ring channel 29 and an intermediary channel 30. The intermediary channel 30 is connected in turn with a ring channel 31 which surrounds the base body 12 of the spindle-shaped component 11, which ring channel 31 can be supplied with the necessary compressed air via a conduit 32. In the case of an exemplary groove-shaped surface area 25 at the tip 13, it can be advantageous when a number of groove-shaped surface areas 25 and correspondingly of grooves 28 are arranged around the yarn withdrawal channel 10. For example, four groove-shaped surface areas 25 can be arranged evenly around the yarn withdrawal channel 10.

The groove-shaped surface areas 25 at the tip 13 as well as the groove 28 can be particularly advantageously created without machining at the tip 13. This is, for example, possible by using a punching process or by direct production of the tip 13 in a moulding tool. The production of the tip 13 is hereby very simply achieved in comparison to the above mentioned prior art.

In FIG. 2 a further exemplary embodiment of the spindle-shaped component 11 and the injection channel 23 is shown. Identical parts have the same reference numbers as in FIG. 1. In order to avoid repetition, reference shall be made to the description accompanying FIG. 1.

In the shown exemplary embodiment in FIG. 2, a groove 33 in the base body 12 in the area of the take-up part 26 is provided in order to supply the injection channel 23 with compressed air from the ring channel 29. The injection channel 23 is formed by a cone-shaped surface area 35 at the tip 13 and by a groove-shaped surface area 34 of the base body 12. The application of the groove 33 and the groove-shaped surface area 34 in the base body 12 can be advantageous when the tip 13 is made of a material which is difficult to form, for example ceramic. The groove-shaped surface area 34 is arranged to the cone-shaped surface area 35 during the assembly of the tip 13 onto the base body 12, so that the injection channel 23 is formed.

Alternatively it can be provided in the embodiment according to FIG. 2, that the surface area 34 of the base body 12 also has a cone-shaped form, and is arranged at a short distance to the cone-shaped surface area 35. This results in turn in a ring-shaped injection channel 23 which is denoted by a broken line having the reference number 34′. The groove 33 or the groove-shaped surface are 34 at the base body 12 can be advantageously formed by milling. As mentioned in FIG. 1, a number of grooves 33 and groove-shaped surface areas 34 can of course also be arranged around the yarn withdrawal channel 10.

The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. 

1. A spindle-shaped component for an air jet spinning arrangement, comprising: a base body; a tip attached to the base body; a yarn withdrawal channel extending through the base body and the tip; an entry opening of the yarn withdrawal channel defined by the tip; and at least one injection channel of the spindle-shaped component which runs into the yarn withdrawal channel, said at least one injection channel being directed in the direction of the entry opening of the yarn withdrawal channel, wherein the at least one injection channel is formed by a surface area of the base body and by a surface area of the tip.
 2. A spindle-shaped component according to claim 1, wherein the at least one injection channel is formed by a cone-shaped surface area of the base body.
 3. A spindle-shaped component according to claim 1, wherein the at least one injection channel is formed by a cone-shaped surface area of the tip.
 4. A spindle-shaped component according to claim 1, wherein the at least one injection channel is formed by a groove-shaped surface area of the tip.
 5. A spindle-shaped component according to claim 1, wherein the at least one injection channel is formed by a groove-shaped surface area of the base body.
 6. A tip for a spindle-shaped component of an air jet spinning arrangement comprising: a yarn withdrawal channel having an entry opening; and a surface area of the tip forming, when joined together with a second surface area of a base body of the spindle-shaped component, at least one injection channel directed towards the entry opening.
 7. A spindle-shaped component according to claim 1, wherein the at least one injection channel is formed by joining together the surface area of the base body with the surface area of the tip.
 8. A spindle-shaped component according to claim 2, wherein the at least one injection channel is formed by joining together the surface area of the base body with the surface area of the tip.
 9. An air jet spinning arrangement, comprising: a spindle shaped component defining a yarn withdrawal channel; an entry opening of the spindle shaped component receiving a yarn into the yarn withdrawal channel; a base body of the spindle shaped component having a shaped outer surface; a tip of the spindle shaped component having a shaped inner surface substantially facing the shaped outer surface; and an injection channel defined between the base body and the tip by the shaped inner surface in cooperation with the shaped outer surface.
 10. The arrangement as claimed in claim 9, wherein the injection channel forms an acute angle with the yarn withdrawal channel, towards the entry opening.
 11. The arrangement as claimed in claim 9, wherein the inner surface and outer surface are substantially cone-shaped.
 12. The arrangement as claimed in claim 9, wherein at least one of the shaped inner surface and outer surface are grooved.
 13. The arrangement as claimed in claim 12, wherein at least one of the shaped inner surface and outer surface comprise multiple grooves defining injection channels. 